/*
 * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/bitmap.h>
#include <linux/dma-mapping.h>
#include <linux/vmalloc.h>
#include <linux/mlx5/driver.h>

#include "mlx5_core.h"

struct mlx5_db_pgdir {
        struct list_head        list;
        unsigned long          *bitmap;
        __be32                 *db_page;
        dma_addr_t              db_dma;
};

/* Handling for queue buffers -- we allocate a bunch of memory and
 * register it in a memory region at HCA virtual address 0.
 */

static void *mlx5_dma_zalloc_coherent_node(struct mlx5_core_dev *dev,
                                           size_t size, dma_addr_t *dma_handle,
                                           int node)
{
        struct device *device = mlx5_core_dma_dev(dev);
        struct mlx5_priv *priv = &dev->priv;
        int original_node;
        void *cpu_handle;

        mutex_lock(&priv->alloc_mutex);
        original_node = dev_to_node(device);
        set_dev_node(device, node);
        cpu_handle = dma_alloc_coherent(device, size, dma_handle,
                                        GFP_KERNEL);
        set_dev_node(device, original_node);
        mutex_unlock(&priv->alloc_mutex);
        return cpu_handle;
}

int mlx5_frag_buf_alloc_node(struct mlx5_core_dev *dev, int size,
                             struct mlx5_frag_buf *buf, int node)
{
        int i;

        buf->size = size;
        buf->npages = DIV_ROUND_UP(size, PAGE_SIZE);
        buf->page_shift = PAGE_SHIFT;
        buf->frags = kzalloc_objs(struct mlx5_buf_list, buf->npages);
        if (!buf->frags)
                goto err_out;

        for (i = 0; i < buf->npages; i++) {
                struct mlx5_buf_list *frag = &buf->frags[i];
                int frag_sz = min_t(int, size, PAGE_SIZE);

                frag->buf = mlx5_dma_zalloc_coherent_node(dev, frag_sz,
                                                          &frag->map, node);
                if (!frag->buf)
                        goto err_free_buf;
                if (frag->map & ((1 << buf->page_shift) - 1)) {
                        dma_free_coherent(mlx5_core_dma_dev(dev), frag_sz,
                                          buf->frags[i].buf, buf->frags[i].map);
                        mlx5_core_warn(dev, "unexpected map alignment: %pad, page_shift=%d\n",
                                       &frag->map, buf->page_shift);
                        goto err_free_buf;
                }
                size -= frag_sz;
        }

        return 0;

err_free_buf:
        while (i--)
                dma_free_coherent(mlx5_core_dma_dev(dev), PAGE_SIZE, buf->frags[i].buf,
                                  buf->frags[i].map);
        kfree(buf->frags);
err_out:
        return -ENOMEM;
}
EXPORT_SYMBOL_GPL(mlx5_frag_buf_alloc_node);

void mlx5_frag_buf_free(struct mlx5_core_dev *dev, struct mlx5_frag_buf *buf)
{
        int size = buf->size;
        int i;

        for (i = 0; i < buf->npages; i++) {
                int frag_sz = min_t(int, size, PAGE_SIZE);

                dma_free_coherent(mlx5_core_dma_dev(dev), frag_sz, buf->frags[i].buf,
                                  buf->frags[i].map);
                size -= frag_sz;
        }
        kfree(buf->frags);
}
EXPORT_SYMBOL_GPL(mlx5_frag_buf_free);

static struct mlx5_db_pgdir *mlx5_alloc_db_pgdir(struct mlx5_core_dev *dev,
                                                 int node)
{
        u32 db_per_page = PAGE_SIZE / cache_line_size();
        struct mlx5_db_pgdir *pgdir;

        pgdir = kzalloc_node(sizeof(*pgdir), GFP_KERNEL, node);
        if (!pgdir)
                return NULL;

        pgdir->bitmap = bitmap_zalloc_node(db_per_page, GFP_KERNEL, node);
        if (!pgdir->bitmap) {
                kfree(pgdir);
                return NULL;
        }

        bitmap_fill(pgdir->bitmap, db_per_page);

        pgdir->db_page = mlx5_dma_zalloc_coherent_node(dev, PAGE_SIZE,
                                                       &pgdir->db_dma, node);
        if (!pgdir->db_page) {
                bitmap_free(pgdir->bitmap);
                kfree(pgdir);
                return NULL;
        }

        return pgdir;
}

static int mlx5_alloc_db_from_pgdir(struct mlx5_db_pgdir *pgdir,
                                    struct mlx5_db *db)
{
        u32 db_per_page = PAGE_SIZE / cache_line_size();
        int offset;
        int i;

        i = find_first_bit(pgdir->bitmap, db_per_page);
        if (i >= db_per_page)
                return -ENOMEM;

        __clear_bit(i, pgdir->bitmap);

        db->u.pgdir = pgdir;
        db->index   = i;
        offset = db->index * cache_line_size();
        db->db      = pgdir->db_page + offset / sizeof(*pgdir->db_page);
        db->dma     = pgdir->db_dma  + offset;

        db->db[0] = 0;
        db->db[1] = 0;

        return 0;
}

int mlx5_db_alloc_node(struct mlx5_core_dev *dev, struct mlx5_db *db, int node)
{
        struct mlx5_db_pgdir *pgdir;
        int ret = 0;

        mutex_lock(&dev->priv.pgdir_mutex);

        list_for_each_entry(pgdir, &dev->priv.pgdir_list, list)
                if (!mlx5_alloc_db_from_pgdir(pgdir, db))
                        goto out;

        pgdir = mlx5_alloc_db_pgdir(dev, node);
        if (!pgdir) {
                ret = -ENOMEM;
                goto out;
        }

        list_add(&pgdir->list, &dev->priv.pgdir_list);

        /* This should never fail -- we just allocated an empty page: */
        WARN_ON(mlx5_alloc_db_from_pgdir(pgdir, db));

out:
        mutex_unlock(&dev->priv.pgdir_mutex);

        return ret;
}
EXPORT_SYMBOL_GPL(mlx5_db_alloc_node);

void mlx5_db_free(struct mlx5_core_dev *dev, struct mlx5_db *db)
{
        u32 db_per_page = PAGE_SIZE / cache_line_size();

        mutex_lock(&dev->priv.pgdir_mutex);

        __set_bit(db->index, db->u.pgdir->bitmap);

        if (bitmap_full(db->u.pgdir->bitmap, db_per_page)) {
                dma_free_coherent(mlx5_core_dma_dev(dev), PAGE_SIZE,
                                  db->u.pgdir->db_page, db->u.pgdir->db_dma);
                list_del(&db->u.pgdir->list);
                bitmap_free(db->u.pgdir->bitmap);
                kfree(db->u.pgdir);
        }

        mutex_unlock(&dev->priv.pgdir_mutex);
}
EXPORT_SYMBOL_GPL(mlx5_db_free);

void mlx5_fill_page_frag_array_perm(struct mlx5_frag_buf *buf, __be64 *pas, u8 perm)
{
        int i;

        WARN_ON(perm & 0xfc);
        for (i = 0; i < buf->npages; i++)
                pas[i] = cpu_to_be64(buf->frags[i].map | perm);
}
EXPORT_SYMBOL_GPL(mlx5_fill_page_frag_array_perm);

void mlx5_fill_page_frag_array(struct mlx5_frag_buf *buf, __be64 *pas)
{
        mlx5_fill_page_frag_array_perm(buf, pas, 0);
}
EXPORT_SYMBOL_GPL(mlx5_fill_page_frag_array);